docs: def read(varin, fname='MS2_L10.mat.txt'):
      '''Read in dataset for variable var
  
      :param varin: Variable for which to read in data.
  
      '''
  
      # # fname = 'MS09_L10.mat.txt'
      # # fname = 'MS09_L05.mat.txt' # has PAR
      # fname = 'MS2_L10.mat.txt' # empty PAR
  
      d = np.loadtxt(fname, comments='*')
  
      if fname == 'MS2_L10.mat.txt':
          var = ['lat', 'lon', 'depth', 'temp', 'density', 'sigma', 'oxygen',
                 'voltage 2', 'voltage 3', 'fluorescence-CDOM', 'fluorescence-ECO',
                 'turbidity', 'pressure', 'salinity', 'RINKO temperature',
                 'RINKO DO - CTD temp', 'RINKO DO - RINKO temp', 'bottom', 'PAR']
      elif (fname == 'MS09_L05.mat.txt') or (fname == 'MS09_L10.mat.txt') or (fname == 'MS08_L12.mat.txt'):
          var = ['lat', 'lon', 'depth', 'temp', 'density', 'sigma', 'oxygen',
                 'voltage 2', 'voltage 3', 'voltage 4', 'fluorescence-CDOM', 'fluorescence-ECO',
                 'turbidity', 'pressure', 'salinity', 'RINKO temperature',
                 'RINKO DO - CTD temp', 'RINKO DO - RINKO temp', 'bottom', 'PAR']
  
      # return data for variable varin
      return d[:, 0], d[:, 1], d[:, 2], d[:, var.index(varin)]